The first of a family of enhanced ground proximity warning systems (EGPWS) to be developed by Honeywell for helicopters will begin flight tests on a Sikorsky S-76 this month.
The Mk XXII system is expected to be certificated and available in the fourth quarter of this year, says Honeywell, which developed the unit from the former AlliedSignal EGPWS family. The flight tests will validate new "look-ahead" algorithms, including a higher resolution terrain database for on and off airport/helipad operation.
The system also incorporates tail strike warning software and auto-rotation altitude awareness cues. The company says one of the hardest challenges was the collection of accurate, high-fidelity terrain and obstacle information for the database.
The MK XXII features "peaks" and "geometric altitude" cues. Peaks provides a digital elevation for the highest and lowest displayed terrain and a representation of sea level and shorelines. The geometric altitude computes a barometric altitude which is designed to eliminate errors resulting from temperature extremes, non-standard pressure altitude conditions and altitude mis-sets.
Source: Flight International
